Re: problems with e1000 and jumboframes

[Krzysztof Oledzki]

On Thu, 3 Aug 2006, Benjamin LaHaise wrote:

> On Thu, Aug 03, 2006 at 03:48:39PM +0200, Arnd Hannemann wrote:
> > However the box is a VIA Epia MII12000 with 1 GB of Ram and 1 GB of swap
> > enabled, so there should be plenty of memory available. HIGHMEM support
> > is off. The e1000 nic seems to be an 82540EM, which to my knowledge
> > should support jumboframes.
>
> > However I can't always reproduce this on a freshly booted system, so
> > someone else may be the culprit and leaking pages?
> >
> > Any ideas how to debug this?
>
> This is memory fragmentation, and all you can do is work around it until
> the e1000 driver is changed to split jumbo frames up on rx.  Here are a
> few ideas that should improve things for you:
>
> 	- switch to a 2GB/2GB split to recover the memory lost to highmem
> 	  (see Processor Type and Features / Memory split)
With 1 GB of RAM full 1GB/3GB (CONFIG_VMSPLIT_3G_OPT) seems to be 
enough...

> 	- increase /proc/sys/vm/min_free_kbytes -- more free memory will
> 	  improve the odds that enough unfragmented memory is available for
> 	  incoming network packets

True. IMO, 65535 is a good starting point.

Best regards,
				Krzysztof Olędzki